Forget about germs, guns or religion, Richard Manning has a new culprit for the decline of mankind: agriculture.

In his new book, "Against the Grain: How Agriculture Has Hijacked Civilization," Manning blames agriculture for just about every human woe you can imagine: poverty, disease, slavery, greed, overpopulation and warfare.

It hasn't helped our sex lives either, Manning says.

The way he sees it, humans took a wrong turn thousands of years ago when they stopped hunting for food and took up the plow. As a result of that questionable career path, Manning says, humans today tend to be desensitized, dull and fat.

"We must hunt for food and sex," Manning writes. "Somewhere along the line we became so focused and so competent in this hunt that we rigged the outcome. To hunt is to be insecure about the immediate future, to experience the nagging fear of want that has driven us to our worst excesses and finest creations. Agriculture rigged this game by allowing storage and wealth, ensuring future food (and sex)," he writes.

Huh? I always thought a ready supply of money, food and sex was a good thing. It's one of many moments in this preachy and thinly supported polemic that made me shake my head or groan with annoyance.

Manning's book arrives at a time when there is a small but growing backlash against industrial-style farming and food production, as evidenced by the explosive growth of farmer's markets and organic products. The excesses of factory food production have also been chronicled in such recent best sellers as Al Franken's "Lies and the Lying Liars Who Tell Them: A Fair and Balanced Look at the Right" and Eric Schlosser's "Fast Food Nation."

But while Franken attacks factory hog farms with sarcastic wit, Manning denounces what he calls "catastrophic agriculture" with such arrogance that I found myself rooting for agribusiness titan Dwayne Andreas, the former chairman of Archer Daniels Midland, whom Manning interviewed for his book.

And where Schlosser dissects McDonald's with a barrage of in-depth interviews and statistics, all of it carefully sourced in 55 pages of notes at the back of the hardcover book, Manning provides little if any support for a broad range of details and pronouncements. He tosses off this sloppiness at the end of the book, where he provides a meager four pages of notes explaining his sources: "I am by habit and training a journalist, not a scholar, and so have a journalist's aversion to footnotes."

As a journalist, I have an aversion to stories in which you can't separate facts from an author's fictions. Manning throws out academic theories without referencing the academic, and frequently presents statistics without attribution or footnote. A typical example:

"Third World countries have seen a fivefold increase in their urban populations between 1950 and 1990. Virtually all of these refugees assume lives of the worst sort of poverty, and much of the blame can be laid on American grain."

All of this may be true, but Manning doesn't tell us where he got the statistics, nor does he provide much proof for his incendiary claim that American grain is to blame. "U.S. grain, free or otherwise, puts Third World farmers out of business, sacking local agriculture and local markets," he writes. "Case studies going back to the 1950s demonstrate this in India, Peru, Egypt, Somalia, Senegal and Haiti."

To be fair, some of Manning's ideas and historical research are interesting, as are certain tidbits of agricultural trivia, although it is often unclear where the information originated.

But many of the central themes of Manning's book--from the reasons why agriculture overtook hunting to the history of how domesticated animals spread diseases--are tepid retreads of chapters in Jared Diamond's authoritative and Pulitzer Prize-winning "Guns, Germs, and Steel." (In Diamond's book, Chapters 6 through 11 cover these topics.)

And too often, even the most arcane facts are smothered by Manning's pretensions. In a tirade against processed food, Manning tells us that he has struggled to figure out the "phenomenon of eating Jell-O":

"Jell-O is a tasteless blob of reconstituted cow's hooves artificially colored, sweetened, and flavored, served in its most revered form with lumps of corn syrup called marshmallows. Even more difficult to explain is that in the Midwest, Jell-O became a status dish, the sort of offering a beaming farm wife would bring to a church social."

It's too bad Manning's research is so shoddy and his writing so heavy-handed, because his claims about the excesses of corporate agriculture and their historical roots certainly merit exploration.